Soft X-ray spectroscopy and imaging of interfacial chemistry in environmental specimens

Interfaces between minerals and water, and minerals and microbes, are chemi cally complex and traditionally have been considered beyond the capabilitie s of surface science techniques, except for model systems under controlled laboratory conditions. We report on some advances in soft x-ray spectroscop y and imaging that make it possible to extract meaningful chemical informat ion about interfaces of specimens that have complex histories, involving en vironmental exposure, These measurements utilize x-ray absorption spectrosc opy, in combination with spatial resolution, in a technique called x-ray sp ectromicroscopy. Examples are drawn from attempts at Mn and Fe speciation o f biologically produced minerals, bio-corrosion deposits and clays. Copyrig ht (C) 1999 John Wiley & Sons, Ltd.